Most of the time, you'll want to keep your fonts simple and easy to read. You should only use fancy fonts, such as script or bold typewriter imitations if they match the theme of your webinar presentation. If a bold, crazy font does fit with your message, you should still limit it to title slides and headings.
- Font Size: Your font size should be at least 28 point or higher. Anything smaller could be difficult for the audience to read, even on full-screen slides.
- Supported Fonts: A list of supported fonts can be accessed here: https://docs.microsoft.com/en-us/typography/font-list/
- Custom Fonts: Are supported but must be embedded with the Powerpoint file.
- Licensed Fonts: Licensed fonts are not supported by webinar.net. Please change them to another font or remove the license restriction before uploading the presentation.

How do I embed my custom fonts in my PPT?
Embed fonts in PowerPoint - Windows Operating Systems
- Click the File tab and then click Options (it's near the bottom left corner of the window).
- In the left column, select the Save tab.
- At the bottom, under Preserve fidelity when sharing this presentation, select the Embed fonts in the file check box.
Do not select - Embed only the characters used in the presentation.
It reduces the file size but limits editing/conversion of the overall PowerPoint file.
Embed fonts in PowerPoint - Microsoft 365 / 2021 for MAC / 2019 for MAC Open the file you want to embed fonts in.
- On the application PowerPoint menu, select Preferences.
- In the dialog box, under Output and Sharing, select Save.
- Under Font Embedding, select Embed fonts in the file.

When you save the file, the fonts used in it will be embedded in the file.

Is embedding your font still not working after upload?
Not all TrueType fonts can be embedded. Font creators can set different options for their fonts, including Non-embeddable, Preview/Print, Editable, and Installable.
To see what level of embedding your installed font is, go to Control Panel in Windows and click Fonts. Clicking on the font shows the Font embeddability setting.
MAC Operating Systems "all fonts" section:

Is your file size too large after embedding fonts? Certain fonts can be very large compared to others, so if the file size is a concern, consider using alternative fonts. If you want to remove the embedding, you can turn off the Embed setting in the Preferences dialog box (described in the procedure above) and save the file.
Then, once you close and re-open the file, a different font is substituted for the font that had been embedded previously.